HiPhish: I'd say Baldur's Gate 1 or Icewind Dale 1 or 2. All three games have you start out at level 1 which makes it easier to get into the game. Baldur's Gate II starts you out at around level 11 because it continues the story, so you are expected to know a few things about the game already. It's not impossible to get into, but harder.
Icewind Dale is all about combat, you create six characters and there is no interactions between them. In Baldur's Gate you create one character and can have up to five NPCs join you in your adventure along the way. It strikes a good balance between combat and story. Planescape Torment is all about the story and the gameplay feels just tacked on and pointless. It would have been better as a point & click adventure. Only play it if you like that kind of game.
Neverwinter Nights 2 is kind of like Baldur's Gate, so that's a good entry point as well, but I don't really like that it's in 3D and you can only have three companions, and later four.
Neverwinter Nights has you play only one character which I found rather boring. Temple of Elemental Evil is all about combat as well, but way too hard for beginners in my opinion.
If you want to go for Baldur's Gate you should also get Baldur's Gate 2 because the games are directly tied together. Another reason is that you can use the Baldur's Gate Trilogy mod to play the first game in the engine of the second one. The original iteration of the Infinity Engine has aged very poorly, I don't recommend playing it vanilla.
Yeah I tried to play Temple of Elemental Evil a few times and found it a bit tough to get into.
